[Lowfer] Frozen trees ??

[JD]

>>> Everything I have read tells me I should lose current when temps are 
>>> freezing but I don't think my ground is a factor.

Goes to show you can't believe everything you read! :)

Seriously, not all soils behave the same under differing temperature and 
moisture content.  What happens at one location is not necessarily what will 
happen at another, either in terms of loss resistance or capacitance between 
antenna and ground.  However, I'm inclined to agree with you that your 
ground system may not be changing all that much in the circumstances you 
describe.

(Just for reference, when you "lose current," is that even after retuning of 
your inductor?  And is there a pattern as to whether colder temperatures 
require more or less inductance?  I'm wondering whether the changes you 
experience are strictly a change in resistance, or in antenna capacitance, 
or both.)

Your tree sap hypothesis is quite plausible!  As I think I mentioned in a 
previous LW Message Board thread where we were talking about tree-supported 
LowFER antennas, my experiences in Georgia led me to believe the same thing. 
Where deciduous trees could be used to support an antenna, there was a 
distinct difference in efficiency between summer (totally lousy) and winter 
(merely poor).  But with pines or other evergreens, the loss was there all 
the time, except maybe during the very coldest of weather...and I couldn't 
even be too sure about an improvement, because at best the signal was so 
poor it was never copied more than a county or two away.  That would be 
consistent with tree sap as a loss factor.

I'd almost be tempted to suggest a Faraday shield for the trees.  I did 
something like that at a radio station once, though it was more for 
lightning secondary-discharge protection of a satellite dish than for RF 
reasons.  But it did seem to reduce the amount of RF current in the trees. 
There's almost no chance of it being practical where the tree is one of the 
supports for the antenna, though.

John